The aspects of the disclosed embodiments are in the field of aircraft with aft propulsion and aft tail sections.
More specifically, the disclosed embodiments propose an architecture having a set of aft aircraft tail sections forming an annular self-enclosed structure, combined with one or more propulsion engines, also located in the aft part of the plane.
On transport planes propelled by jet engines or turboshaft engines, such as unducted fans or UDF, as they are called in English, the aft tail sections most often have, in the so-called basic form of the approximately vertical aerodynamic surfaces, the vertical tail section, and others approximately horizontal, the horizontal tail section, attached to the aft part of the fuselage, aerodynamic surfaces that ensure the stability of the aircraft in flight and make it possible to control it by means of rudders and elevators attached to said aerodynamic surfaces.
This form of basic conventional tail section is widely used on many civilian transport planes, like the Airbus A320, for example.
In less frequently used forms, particularly on civilian transport planes, the horizontal tail section is attached to the vertical tail section either on top of the latter, the so-called T-shaped tail section, for example on the Bael 46 plane, or at mid-height position, the so-called cruciform tail section, on the Aerospatiale SE210 Caravelle.
In other forms also known, the vertical tail section has two vertical aerodynamic surfaces attached to the end of the horizontal tail section, the so-called H-shaped tail section, as on the Nord2500 Noratlas.
Another known shape of the aft tail section consists of two surfaces inclined between the vertical and the horizontal to form a V whose combination performs the functions of both vertical and horizontal aerodynamic surfaces. This type of so-called butterfly tail section is used mainly on the CM170 Fouga Magister.
The choice of the shape of tail section for an aircraft generally depends on aerodynamic and structural considerations, and is influenced by the position and type of propulsion engines that generate both aerodynamic and structural stresses, but also on operational safety since engine failures, such as a turbine explosion, should not have such an impact on the tail sections that the aircraft can no longer be controlled.
On current aircraft, the different basic tail section shapes, where the aerodynamic surfaces of the tail section are not individually attached to the fuselage, have aircraft architectures with aft tail sections, but the known shapes—T, cruciform, H and V—are very close in the design of their basic shape with no overall aerodynamic and structural optimization of the tail section units with propulsion engines.